Early Exploration - Reactors designed/built by Argonne National Laboratory Early Exploration Tweet BOOKSHELF “Plentiful Energy: The Story of the Integral Fast Reactor” by Charles E. Till and Yoon Chang gives the history of the IFR at Argonne. The book is available on Amazon.com… More about the IFR » Early Exploration Early exploration nuclear reactors designed by the Manhattan Project's Metallurgical Laboratory, the direct predecessor to Argonne National Laboratory, began the development of nuclear technology. CP-3 CP-1 (Chicago Pile 1 Reactor) This drawing depicts the historic Dec. 2, 1942, event -- the first controlled, self-sustaining nuclear chain reaction. It took place under the abandoned football stands at the University of Chicago. Click on photo to view a larger image. Chicago Pile 1 was the world's first nuclear reactor, built in 1942 by Nobel Prize winner Enrico Fermi. The reactor was built underneath the University of Chicago's Stagg Field football stadium. On Dec.

2, 1942, Enrico Fermi and 48 of his colleagues succeed in achieving in this reactor the world’s first man-made controlled nuclear chain reaction, thereby establishing the ability of mankind to control the release of nuclear energy. He and other scientists from that group later founded Argonne National Laboratory. Scale model of CP-1 reactor. Courtesy Archival Photographic Files, [apf2-00504], Special Collections Research Center, University of Chicago Library. Click on photo to view a larger image. Download image from Flickr The photograph at right shows a scale model depicting Fermi’s reactor setup on that day in 1942. The model shows a segment of the football stadium and gives a perspective on where the reactor was located under the stands. Fermi and his colleagues were assembled on the balcony to the right to observe the instruments recording the neutron intensity in the pile. After the reactor had sustained the chain reaction for 28 minutes the operators to the right of the reactor (in the left foreground of the photo) pushed in a cadmium control rod called zip, which absorbed neutrons and ended the chain reaction.

The reactor fuel was lumps of uranium metal and uranium oxide; these were spaced on a cubic lattice within layers of graphite, with some graphite layers containing only uranium metal pseudospheres, some only uranium oxide pseudospheres, and some containing both. The pile was built by alternating graphite layers seeded with uranium metal and/or uranium oxide with layers of solid graphite blocks. The completed reactor contained 57 layers, which was about one layer beyond the critical stage needed to sustain the chain reaction. Early in 1943, CP-1 was dismantled and moved to a less-populated site in the "Argonne Forest" section of the Cook County Forest Preserve in Palos Park. That part of the forest has since been renamed, but its appellation survives today in the name of Argonne National Laboratory. For more information on CP-1 : Watch the video on YouTube (posted on May 15, 2014) CP-2 (Chicago Pile 2 Reactor) In early 1943, Chicago Pile 1 was dismantled at the University of Chicago, moved to the Argonne Forest section of the Palos Hills Forest Preserve, and renamed Chicago Pile 2.

Click on photo to view a larger image. In early 1943 Manhattan Engineer District disassembled Chicago Pile 1 and rebuilt it at Palos Park, IL, as Chicago Pile 2. CP-2 had a thermal- power level of 10 kW. The fuel for CP-2 was natural uranium (uranium in which the natural abundance of the isotopes uranium-234, uranium-235, and uranium-238 has not been altered). A small laboratory atop the 14,000-ton reactor provided space for limited experiments using neutrons from the reactor's core. The reactor's face contained ports through which materials could be inserted into the core for irradiation. For more information on CP-2: Evaluation of the ZPR-6 assembly for DOE Nuclear Criticality Safety Program ANL-NT-175 (April, 2001) [5.8MB] — Report featuring detailed descriptions of all the ZPR-6 assemblies, also contains an extensive bibliography of technical reports that detail the results of all the experiments on ZPR-6.

History of MET Lab Section C-I, April 1942--April 1943 [40MB], by Glenn T. Seaborg, February 01, 1977 — This is a report assembled in the 1970’s by Glenn Seaborg on his work at the Met Lab in the April 1942 to April 1943 period. See page 201 of the report for his personal account of how Plutonium was isolated by the microchemists at the Met Lab. Having a Meltdown? Cool Your Engines with a Nuclear Power Trip Dennis Jacobs from the BurridgePatch wrote a great article about Argonne National Laboratory's surroundings and why they are definitely worth a visit -- burrridge.patch.com blogs (Sep. 7, 2011) CP-3 (Chicago Pile 3 Reactor) The Chicago Pile-3 reactor. Click on photo to view a larger image. Chicago Pile 3 was the world's first "heavy-water moderated" reactor. It was designed by Eugene Wigner; at Enrico Fermi's request, Walter Zinn directed its construction in the Argonne Forest in 1943.

Chicago Pile 3 achieved criticality in 1944. The fuel was, as in the case of the CP-2 reactor , natural uranium. CP-3 was dismantled in January 1950 because of suspected corrosion of the aluminum cladding around some of the fuel rods. The natural uranium fuel in CP-3 was replaced with enriched uranium (uranium in which the amount of uranium-235 in the fuel has been increased from its naturally occurring abundance). The redesigned reactor, named CP-3’ ("CP-3 prime"), became operational in May 1950. CP-3’ shut down in 1954. CP-3 was shared with the Canadians, who used it in the design of the Canadian NRX reactor, from which the 27 CANDU commercial power reactors evolved. Research programs conducted at CP-3 and CP-3’ included reactor physics studies, fission product separations, tritium recovery from irradiated lithium, and studies of radionuclide metabolism in laboratory animals.

For more information on CP-3 : Enrico Fermi and the First Self-Sustaining Nuclear Chain Reaction Enrico Fermi and the First Self-Sustaining Nuclear Chain Reaction Patents · Audio/Video Clips · Selected by NSTA for SciLinks "The President of the United States of America ... for especially meritorious contributions to the development, use, or control of atomic energy, grant[s] an award of merit to Enrico Fermi for his contributions to basic neutron physics and the achievement of the controlled nuclear chain reaction." – Excerpt from Enrico Fermi Award signed by President Dwight D. Eisenhower on December 1, 1954. Courtesy Argonne National Laboratory Enrico Fermi was born in Rome, Italy, on September 29, 1901. The son of a railroad official, he studied at the University of Pisa from 1918 to 1922 and later at the universities of Leyden and Gottingen. He became professor of theoretical physics at the University of Rome in 1927.

Fermi's accomplishments were in both theoretical and experimental physics, a unique feat in an age in which scientific endeavors have tended to specialize on one aspect or the other. Fermi received the Nobel Prize in 1938 for "his discovery of new radioactive elements produced by neutron irradiation, and for the discovery of nuclear reactions brought about by slow neutrons." Fermi and his family used the opportunity offered by his trip to Sweden for the awards ceremonies to come to the United States where Fermi accepted a position as professor of physics at Columbia University. Fermi moved to the University of Chicago to be in charge of the first major step in making feasible the building of the atomic bomb. In the squash courts under the west stand of the University's Stagg Field, Fermi supervised the design and assembly of an "atomic pile", a code word for an assembly that in peacetime would be known as a "nuclear reactor".

Today, a plaque at the site reads: "On December 2, 1942, man achieved here the first self-sustaining chain reaction and thereby initiated the controlled release of nuclear energy." Fermi's momentous accomplishments caused him to be recognized as one of the great scientists of the 20th century. Following his death on November 28, 1954, a number of science institutions and awards have been named in his honor. Top Resources with Additional Information Additional information about Enrico Fermi and his work is available in full-text DOE reports and on the Web. Documents: How the first chain reaction changed science | The University of Chicago The University of Chicago How the first chain reaction changed science Legacy of 1942 breakthrough on campus includes advances in many fields By Steve Koppes Photo by Robert Kozloff “ All of us . . . knew that with the advent of the chain reaction, the world would never be the same again.” —Samuel K. Allison UChicago physicist The Atomic Age began at 3:25 p.m. on Dec.

2, 1942—quietly, in secrecy, on a squash court under the west stands of old Stagg Field at the University of Chicago. Today, Henry Moore’s “Nuclear Energy” sculpture and the Mansueto Library occupy the area at the corner of Ellis Avenue and 57th Street where Enrico Fermi and his colleagues engineered the first controlled, self-sustaining nuclear chain reaction 70 years ago. Their experiment was a key step in the Manhattan Project to develop the atomic bomb during World War II. That initial chain reaction was too weak to power even a single light bulb. It nevertheless transformed the world, and the University of Chicago along with it, in a range of endeavors spanning physics, chemistry, interdisciplinary research, policy analysis, and nuclear medicine. Even in 1942, those present at the historic event sensed how influential their work would be. “All of us . . . knew that with the advent of the chain reaction, the world would never be the same again,” former UChicago physicist Samuel K. Allison wrote at the time. That first chain reaction’s complex legacy includes the peaceful uses of nuclear energy, the terrible power of nuclear weapons, and a new era of other scientific and technological advances.

After the war, UChicago founded the Institute for Nuclear Studies and the Institute for the Study of Metals. Later renamed the Enrico Fermi and the James Franck institutes, they enabled the University to retain much of the intellectual talent that had assembled on campus to work on the Manhattan Project. Another outgrowth of the project was Argonne National Laboratory , which conducts basic and applied research in many major scientific disciplines. Today, Argonne is a partner in the Institute for Molecular Engineering , which is bringing leading scientists and engineers to a groundbreaking initiative to conduct research at the molecular level. “What we see here is a legacy of connection that we’re still building upon, a way to try to redefine engineering for the 21st century," said Provost Thomas Rosenbaum, the John T. Wilson Distinguished Service Professor in Physics. Building the pile Though Fermi’s team was engaged in the biggest secret project of World War II, they discussed technical issues under a tree on the Main Quad, which they deemed safe from eavesdroppers. In the middle of the day on which they produced the first chain reaction, they took a customary lunch break at Hutchinson Commons.

“Don’t imagine that they were able to achieve a chain reaction on the first try,” says Roger Hildebrand , the Samuel K. Allison Distinguished Service Professor Emeritus in Physics. “They built and rebuilt stacks of uranium, uranium oxide, and graphite 30 times before they were ready for the final test.” Chicago Pile Number One, or CP-1 for short, consisted of 40,000 graphite blocks that enclosed 19,000 pieces of uranium metal and uranium oxide fuel. The scientists of what was then called the Metallurgical Laboratory, or “Met Lab,” had arranged the graphite in layers within a 24-foot-square wooden framework. Hildebrand had started his work on the Manhattan Project as an undergraduate chemistry major at the University of California, Berkeley. He worked for Nobel laureate Ernest Lawrence, namesake of the Lawrence Livermore and Lawrence Berkeley national laboratories, using Berkeley’s cyclotron accelerator to transmute uranium into plutonium, an element believed to have potential for driving a chain reaction. The samples irradiated in Berkeley and another lab in St. Louis ended up in the James Herbert Jones Laboratory, just one block south of old Stagg Field.

There, in Jones Lab’s Room 405, future Nobel laureate Glenn Seaborg achieved an important steppingstone on the way to the Atomic Age. He weighed the first visible, pinhead-sized sample of plutonium. It wasn’t much, but enough to measure its chemical and metallurgical properties. The potential hazards of nuclear power were evident even in those early days, but the war effort took priority. The Japanese had bombed Pearl Harbor on Dec. 7, 1941. Germany and Italy declared war on the United States four days later. “They were advancing everywhere, they were conquering everywhere, and they were working on an atomic bomb,” Hildebrand said of the Germans. “The consequence of losing a nuclear race was the preoccupation of everyone who knew that a nuclear bomb might be possible.” Outgrowths of chain reaction success The scientific staff of the Metallurgical Laboratory founded the Atomic Scientists of Chicago on Sept. 26, 1945—just weeks after the United States dropped the atomic bomb on Hiroshima and Nagasaki. The group published the first issue of the Bulletin of the Atomic Scientists of Chicago on Dec. 10, 1945.

The Bulletin’s Doomsday Clock still stands as a symbol of humanity’s vulnerability to man-made catastrophe, with an agenda that expanded from nuclear weapons to include climate change and biological weapons. Medical research gained unexpected benefits from the wartime research. In the early 1950s, the Atomic Energy Commission funded the Argonne Cancer Research Hospital, which became the Franklin McLean Institute, 5841 S. Ellis Ave., in 1973. The Argonne Hospital successfully pioneered the use of radiation in cancer treatment, with efforts later expanding to include radiological innovations in the diagnosis and treatment of other diseases. Although the University of Chicago already was renowned in physics and chemistry before World War II, scientists who worked on the Manhattan Project helped those departments attain new research prominence following the war. Numerous UChicago scientists who were part of the war effort won Nobel Prizes for scholarly work in the postwar period, including Owen Chamberlain, Eugene P. Wigner, and Glenn Seaborg. Fermi, one of the most important scientists of the 20th century, became an inspiring teacher at UChicago after the war before dying of stomach cancer in 1954.

The National Accelerator Laboratory in Batavia was renamed in Fermi’s honor in 1974, and became known as Fermilab , the site of numerous fundamental advances in particle physics. UChicago builds for the future Today, the William Eckhart Research Center is rising from a construction site directly across the street from where Fermi and his associates achieved the first controlled, self-sustaining nuclear chain reaction. The Eckhart Center will occupy the site of the former Research Institutes building, where Fermi and many other Manhattan Project veterans did transformative research. UChicago scientists formally honored the Research Institutes’ legacy in June 2011, when they publicly revealed the contents of the time capsule that Fermi had sealed within the Research Institutes building cornerstone nearly 62 years earlier. In retrospect the cornerstone’s contents, which included booklets on the institutes and a sketch of their building, barely hinted at the accomplishments that would follow. That inspiring legacy survives to this day, said Robert Fefferman, dean of the University’s Physical Sciences Division. “This is not just something about the distant past,” Fefferman, remarked at the cornerstone unveiling ceremony.

“This is something that continues, and we’re extremely proud of the grand tradition of science here.” Enrico Fermi | Atomic Heritage Foundation Atomic Heritage Foundation Enrico Fermi Enrico Fermi (1901-1954) was an Italian physicist and recipient of the 1938 Nobel Prize in Physics. In 1942, Fermi relocated to the Chicago Met Lab, where he built an experimental reactor pile under Stagg Field at the University of Chicago. Construction was completed on December 1 and the reactor went critical the next day. In August 1944, Fermi went to Los Alamos as an associate director and key consultant. At the Hanford site in 1944, Fermi inserted the first uranium slug into the “B” pile reactor, just as he had for the first pile in the CP-1 reactor two years earlier. During the "B" reactor test, Fermi was in charge of directing operations. His meticulous calculations, completed on a slide rule, determined how much uranium needed to be added to the reactor; measurements confirmed that his calculations were astoundingly accurate. The start-up failed, however, when the reactor shut itself down.

John Wheeler hypothesized that some unknown substance was forming during fission and absorbing the neutrons needed to sustain the reaction. Fermi immediately agreed with Wheeler’s explanation and began working with him to find the unknown poison. By comparing the half-life of different radioactive gases with the amount of time that the reactor failed Wheeler and Fermi were able to discover that the problem substance was xenon-135. At Los Alamos, Fermi served as an associate director of the laboratory. After the Trinity test, Fermi remarked: “My first impression of the explosion was the very intense flash of light, and a sensation of heat on the parts of the body that were exposed. Although I did not directly look towards the object, I had the full impression that suddenly the countryside became brighter than in full daylight.” Ever the inquiring scientist, Fermi took the opportunity to conduct an experiment of his own. Just as the blast hit, he dropped several pieces of paper. Having measured their displacement and making a quick mental calculation, Fermi declared: “That corresponds to the blast produced by ten thousand tons of TNT.” Fermi advised the Interim Committee on target selection, recommending the bombs be used without warning against an industrial target.

In 1944, Fermi became American citizen, and at the end of the war he accepted a professorship at the University of Chicago's Institute for Nuclear Studies, a position which he held until his untimely death. There he turned his attention to high-energy physics, and led investigations into the pion-nucleon interaction. He also served on the Atomic Energy Commission's General Advisory Committee. The Enrico Fermi Award, a prestigious science and technology honor given by the US government, bears his name. Scientific Contributions In 1938, Fermi was awarded the Nobel Prize in Physics "for his demonstrations of the existence of new radioactive elements produced by neutron irradiation, and for his related discovery of nuclear reactions brought about by slow neutrons." His research on the bombardment of elements to produce fissionable isotopes was critical to the success of the Manhattan Project. For more information about Fermi's scientific research and accomplishments, visit the Nobel Prize website . Enrico Fermi's Timeline 1901 Sep 29th Born in Rome, Italy. 1918 Won a fellowship of the Scuola Normale Superiore of Pisa.

1922 Received his Laurea degree in physics from the Scuola Normale Superiore of Pisa. Franco Rasetti, Enrico Fermi, and Emilio Segre in academic dress General Groves pinning an award on Enrico Fermi Enrico Fermi Enrico Fermi. Photo courtesy of Argonne National Laboratory. Enrico Fermi and his wife, Laura Related Profiles Enrico Fermi - Hanford Site HANFORD Site Department of Energy Hanford Site Hanford Site | Text Albert Einstein was one of the scientists who recommended that President Franklin Delano Roosevelt consider making atomic bombs in World War II. Enrico Fermi was one of the scientists who made it happen. Fermi was born in Italy, but came to the United States in 1938. Like Einstein, Fermi was a brilliant man, who also won a Nobel Prize for physics. In 1942, after President Roosevelt had ordered that an atomic weapon be made, Fermi and his team at the University of Chicago were responsible for building the first nuclear reactor. A nuclear reactor is the machine which makes plutonium, the most important ingredient of an atomic weapon.

When Fermi proved that his small nuclear reactor would work, President Roosevelt ordered that much larger reactors would be built at what is now the Hanford Site. Fermi, as the person who designed the first reactor at the University of Chicago, was also very important in building Hanford’s nuclear reactors. As a matter of fact, he was so important, that he had a bodyguard assigned to protect him at all times! Just to be on the safe side, Fermi was even given a different name, called an alias, so that people wouldn’t know who he really was. At Hanford, Fermi was known to most people as Mr. Farmer, not Enrico Fermi! In September of 1944, Fermi was at Hanford when Hanford’s first nuclear reactor, the B Reactor, was turned on. The B Reactor was the first, full-scale nuclear reactor ever built in the world, and because of that, scientists weren’t sure it would work the way it was designed to. When the B Reactor went operational for the first time, it ran perfectly for about three hours, but then, the reactor stopped working properly.

Fermi and some other scientists worked day and night to try and figure out why the B Reactor didn’t work like it was supposed to and they eventually solved the problems. By December of ’44, the B Reactor was working as intended and plutonium was being produced. Fermi was also on hand when the plutonium from Hanford’s B Reactor was used in the testing of the world’s first atomic bomb in July of 1945. Called the Trinity Test, the bomb was blown up in the New Mexico desert. Less than a month later, the two atomic bombs produced by the United States were exploded over Japan and helped to end World War II. The first bomb blew up over Hiroshima, Japan on August 6, 1945 and was called “Little Boy”. The second bomb was called “Fat Man”, and it blew up over Nagasaki, Japan on August 9. Fat Man was the bomb that was made using the plutonium which came from the Hanford nuclear reactors. Biography & Patents of Italian Inventor Enrico Fermi Inventors Enrico Fermi.

Courtesy of DOE The Inventors Hall of Fame states that, "Enrico Fermi and Leo Szilard discovered the first nuclear reactor in which nuclear chain reactions are initiated, controlled, and sustained at a steady observable rate." Today, Enrico Fermi’s nuclear reactor is in common use in nuclear power plants. Enrico Fermi and Leo Szilard received U.S. patent #2,708,656 for the nuclear reactor. Enrico Fermi Biography Enrico Fermi was born in Rome, Italy, on September 29, 1901. The son of a railroad official, he studied at the University of Pisa from 1918 to 1922 and later at the universities of Leyden and Gottingen. He became professor of theoretical physics at the University of Rome in 1927. In 1933, he developed the theory of beta decay, postulating that the newly-discovered neutron decaying to a proton emits an electron and a particle which he called a "neutrino". continue reading below our video The Manhattan Project The theory developed to explain this interaction later resulted in recognition of the weak interaction force.

Investigation into the weak force has been one of the major areas of study at Fermilab. Experimentally, Enrico Fermi and his colleagues, during the early 1930's, studied in detail the theory of neutrons; they bombarded most of the elements in the periodic table with them. They slowed down the neutrons, and among other things, produced a strange new product when bombarding uranium with neutrons which later was recognized to be a splitting of the uranium atoms. Enrico Fermi - 1938 Nobel Prize Enrico Fermi received the Nobel Prize in 1938 for "his discovery of new radioactive elements produced by neutron irradiation, and for the discovery of nuclear reactions brought about by slow neutrons." Fermi and his family used the opportunity offered by his trip to Sweden for the awards ceremonies to come to the United States where Fermi accepted a position as professor of physics at Columbia University. At that time it was recognized that nuclear fission (the splitting of the atom) had taken place in Fermi's and other similar experiments. Scientists felt that this principle might be applied to construct an " atomic bomb ".

With World War II raging in Europe, the ability to produce such a bomb was of the greatest importance in the balance of power in the world. Enrico Fermi - Work on Atomic Bomb Enrico Fermi moved to the University of Chicago to be in charge of the first major step in making feasible the building of the atomic bomb . In the squash courts under the west stand of the University's Stagg Field, Fermi supervised the design and assembly of an "atomic pile", a code word for an assembly that in peacetime would be known as a "nuclear reactor". Today, a plaque at the site reads: "On December 2, 1942, man achieved here the first self-sustaining chain reaction and thereby initiated the controlled release of nuclear energy." Enrico Fermi was the prime mover in the design of the synchrocyclotron at the university which was, at the time of its completion, one of the most powerful atom smashers in the world. Fermi’s momentous accomplishments caused him to be recognized as one of the great scientists of the 20th century.

Following his death on November 28, 1954, a number of science institutions and awards have been named in his honor. History of Nuclear Energy - World Nuclear Association Outline History of Nuclear Energy (Updated March 2014) The science of atomic radiation, atomic change and nuclear fission was developed from 1895 to 1945, much of it in the last six of those years. Over 1939-45, most development was focused on the atomic bomb. From 1945 attention was given to harnessing this energy in a controlled fashion for naval propulsion and for making electricity. Since 1956 the prime focus has been on the technological evolution of reliable nuclear power plants. Exploring the nature of the atom Uranium was discovered in 1789 by Martin Klaproth, a German chemist, and named after the planet Uranus. Ionising radiation was discovered by Wilhelm Rontgen in 1895, by passing an electric current through an evacuated glass tube and producing continuous X-rays.

Then in 1896 Henri Becquerel found that pitchblende (an ore containing radium and uranium) caused a photographic plate to darken. He went on to demonstrate that this was due to beta radiation (electrons) and alpha particles (helium nuclei) being emitted. Villard found a third type of radiation from pitchblende: gamma rays, which were much the same as X-rays. Then in 1896 Pierre and Marie Curie gave the name 'radioactivity' to this phenomenon, and in 1898 isolated polonium and radium from the pitchblende. Radium was later used in medical treatment. In 1898 Samuel Prescott showed that radiation destroyed bacteria in food. In 1902 Ernest Rutherford showed that radioactivity as a spontaneous event emitting an alpha or beta particle from the nucleus created a different element. He went on to develop a fuller understanding of atoms and in 1919 he fired alpha particles from a radium source into nitrogen and found that nuclear rearrangement was occurring, with formation of oxygen.

Niels Bohr was another scientist who advanced our understanding of the atom and the way electrons were arranged around its nucleus through to the 1940s. By 1911 Frederick Soddy discovered that naturally-radioactive elements had a number of different isotopes (radionuclides), with the same chemistry. Also in 1911, George de Hevesy showed that such radionuclides were invaluable as tracers, because minute amounts could readily be detected with simple instruments. In 1932 James Chadwick discovered the neutron. Also in 1932 Cockcroft and Walton produced nuclear transformations by bombarding atoms with accelerated protons, then in 1934 Irene Curie and Frederic Joliot found that some such transformations created artificial radionuclides. The next year Enrico Fermi found that a much greater variety of artificial radionuclides could be formed when neutrons were used instead of protons. Fermi continued his experiments, mostly producing heavier elements from his targets, but also, with uranium, some much lighter ones.

At the end of 1938 Otto Hahn and Fritz Strassmann in Berlin showed that the new lighter elements were barium and others which were about half the mass of uranium, thereby demonstrating that atomic fission had occurred. Lise Meitner and her nephew Otto Frisch, working under Niels Bohr, then explained this by suggesting that the neutron was captured by the nucleus, causing severe vibration leading to the nucleus splitting into two not quite equal parts. They calculated the energy release from this fission as about 200 million electron volts. Frisch then confirmed this figure experimentally in January 1939. This was the first experimental confirmation of Albert Einstein's paper putting forward the equivalence between mass and energy, which had been published in 1905. Harnessing nuclear fission These 1939 developments sparked activity in many laboratories. Hahn and Strassmann showed that fission not only released a lot of energy but that it also released additional neutrons which could cause fission in other uranium nuclei and possibly a self-sustaining chain reaction leading to an enormous release of energy.

This suggestion was soon confirmed experimentally by Joliot and his co-workers in Paris, and Leo Szilard working with Fermi in New York. Bohr soon proposed that fission was much more likely to occur in the uranium-235 isotope than in U-238 and that fission would occur more effectively with slow-moving neutrons than with fast neutrons, the latter point being confirmed by Szilard and Fermi, who proposed using a 'moderator' to slow down the emitted neutrons. Bohr and Wheeler extended these ideas into what became the classical analysis of the fission process, and their paper was published only two days before war broke out in 1939. Another important factor was that U-235 was then known to comprise only 0.7% of natural uranium, with the other 99.3% being U-238, with similar chemical properties. Hence the separation of the two to obtain pure U-235 would be difficult and would require the use of their very slightly different physical properties. This increase in the proportion of the U-235 isotope became known as 'enrichment'.

The remaining piece of the fission/atomic bomb concept was provided in 1939 by Francis Perrin who introduced the concept of the critical mass of uranium required to produce a self-sustaining release of energy. His theories were extended by Rudolf Peierls at Birmingham University and the resulting calculations were of considerable importance in the development of the atomic bomb. Perrin's group in Paris continued their studies and demonstrated that a chain reaction could be sustained in a uranium-water mixture (the water being used to slow down the neutrons) provided external neutrons were injected into the system. They also demonstrated the idea of introducing neutron-absorbing material to limit the multiplication of neutrons and thus control the nuclear reaction (which is the basis for the operation of a nuclear power station). Peierls had been a student of Werner Heisenberg, who from April 1939 presided over the German nuclear energy project under the German Ordnance Office. Initially this was directed towards military applications, but by 1942 the military objective was abandoned as impractical. However, the existence of the German Uranverein project provided the main incentive for wartime development of the atomic bomb by Britain and the USA.

Nuclear physics in Russia Russian nuclear physics predates the Bolshevik Revolution by more than a decade. Work on radioactive minerals found in central Asia began in 1900 and the St Petersburg Academy of Sciences began a large-scale investigation in 1909. The 1917 Revolution gave a boost to scientific research and over 10 physics institutes were established in major Russian towns, particularly St Petersburg, in the years which followed. In the 1920s and early 1930s many prominent Russian physicists worked abroad, encouraged by the new regime initially as the best way to raise the level of expertise quickly. These included Kirill Sinelnikov, Pyotr Kapitsa and Vladimir Vernadsky. By the early 1930s there were several research centres specialising in nuclear physics. Kirill Sinelnikov returned from Cambridge in 1931 to organise a department at the Ukrainian Physico-Technical Institute (FTI) in Kharkov which had been set up in 1928.

Academician Abram Ioffe formed another group at Leningrad FTI (including the young Igor Kurchatov), which in 1933 became the Department of Nuclear Physics under Kurchatov with four separate laboratories. By the end of the decade, there were cyclotrons installed at the Radium Institute and Leningrad FTI (the biggest in Europe). But by this time many scientists were beginning to fall victim to Stalin's purges -- half the staff of Kharkov FTI, for instance, was arrested in 1939. Nevertheless, 1940 saw great advances being made in the understanding of nuclear fission including the possibility of a chain reaction. At the urging of Kurchatov and his colleagues, the Academy of Sciences set up a "Committee for the Problem of Uranium" in June 1940 chaired by Vitaly Khlopin, and a fund was established to investigate the central Asian uranium deposits. Germany's invasion of Russia in 1941 turned much of this fundamental research to potential military applications. Conceiving the atomic bomb British scientists had kept pressure on their government.

The refugee physicists Peierls and Frisch (who had stayed in England with Peierls after the outbreak of war), gave a major impetus to the concept of the atomic bomb in a three-page document known as the Frisch-Peierls Memorandum. In this they predicted that an amount of about 5kg of pure U-235 could make a very powerful atomic bomb equivalent to several thousand tonnes of dynamite. They also suggested how such a bomb could be detonated, how the U-235 could be produced, and what the radiation effects might be in addition to the explosive effects. They proposed thermal diffusion as a suitable method for separating the U-235 from the natural uranium. This memorandum stimulated a considerable response in Britain at a time when there was little interest in the USA. A group of eminent scientists known as the MAUD Committee was set up in Britain and supervised research at the Universities of Birmingham, Bristol, Cambridge, Liverpool and Oxford. The chemical problems of producing gaseous compounds of uranium and pure uranium metal were studied at Birmingham University and Imperial Chemical Industries (ICI).

Dr Philip Baxter at ICI made the first small batch of gaseous uranium hexafluoride for Professor James Chadwick in 1940. ICI received a formal contract later in 1940 to make 3kg of this vital material for the future work. Most of the other research was funded by the universities themselves. Two important developments came from the work at Cambridge. The first was experimental proof that a chain reaction could be sustained with slow neutrons in a mixture of uranium oxide and heavy water, ie. the output of neutrons was greater than the input. The second was by Bretscher and Feather based on earlier work by Halban and Kowarski soon after they arrived in Britain from Paris. When U-235 and U-238 absorb slow neutrons, the probability of fission in U-235 is much greater than in U-238. The U-238 is more likely to form a new isotope U-239, and this isotope rapidly emits an electron to become a new element with a mass of 239 and an Atomic Number of 93.

This element also emits an electron and becomes a new element of mass 239 and Atomic Number 94, which has a much greater half-life. Bretscher and Feather argued on theoretical grounds that element 94 would be readily fissionable by slow and fast neutrons, and had the added advantages that it was chemically different to uranium and therefore could easily be separated from it. This new development was also confirmed in independent work by McMillan and Abelson in the USA in 1940. Dr Kemmer of the Cambridge team proposed the names neptunium for the new element # 93 and plutonium for # 94 by analogy with the outer planets Neptune and Pluto beyond Uranus (uranium, element # 92). The Americans fortuitously suggested the same names, and the identification of plutonium in 1941 is generally credited to Glenn Seaborg. Developing the concepts By the end of 1940 remarkable progress had been made by the several groups of scientists coordinated by the MAUD Committee and for the expenditure of a relatively small amount of money.

All of this work was kept secret, whereas in the USA several publications continued to appear in 1940 and there was also little sense of urgency. By March 1941 one of the most uncertain pieces of information was confirmed - the fission cross-section of U-235. Peierls and Frisch had initially predicted in 1940 that almost every collision of a neutron with a U-235 atom would result in fission, and that both slow and fast neutrons would be equally effective. It was later discerned that slow neutrons were very much more effective, which was of enormous significance for nuclear reactors but fairly academic in the bomb context. Peierls then stated that there was now no doubt that the whole scheme for a bomb was feasible provided highly enriched U-235 could be obtained. The predicted critical size for a sphere of U-235 metal was about 8kg, which might be reduced by use of an appropriate material for reflecting neutrons. However, direct measurements on U-235 were still necessary and the British pushed for urgent production of a few micrograms. The final outcome of the MAUD Committee was two summary reports in July 1941.

One was on 'Use of Uranium for a Bomb' and the other was on 'Use of Uranium as a Source of Power'. The first report concluded that a bomb was feasible and that one containing some 12 kg of active material would be equivalent to 1,800 tons of TNT and would release large quantities of radioactive substances which would make places near the explosion site dangerous to humans for a long period. It estimated that a plant to produce 1kg of U-235 per day would cost ?5 million and would require a large skilled labour force that was also needed for other parts of the war effort. Suggesting that the Germans could also be working on the bomb, it recommended that the work should be continued with high priority in cooperation with the Americans, even though they seemed to be concentrating on the future use of uranium for power and naval propulsion. The second MAUD Report concluded that the controlled fission of uranium could be used to provide energy in the form of heat for use in machines, as well as providing large quantities of radioisotopes which could be used as substitutes for radium.

It referred to the use of heavy water and possibly graphite as moderators for the fast neutrons, and that even ordinary water could be used if the uranium was enriched in the U-235 isotope. It concluded that the 'uranium boiler' had considerable promise for future peaceful uses but that it was not worth considering during the present war. The Committee recommended that Halban and Kowarski should move to the USA where there were plans to make heavy water on a large scale. The possibility that the new element plutonium might be more suitable than U-235 was mentioned, so that the work in this area by Bretscher and Feather should be continued in Britain. The two reports led to a complete reorganisation of work on the bomb and the 'boiler'. It was claimed that the work of the committee had put the British in the lead and that "in its fifteen months' existence it had proved itself one of the most effective scientific committees that ever existed". The basic decision that the bomb project would be pursued urgently was taken by the Prime Minister, Winston Churchill, with the agreement of the Chiefs of Staff.

The reports also led to high level reviews in the USA, particularly by a Committee of the National Academy of Sciences, initially concentrating on the nuclear power aspect. Little emphasis was given to the bomb concept until 7 December 1941, when the Japanese attacked Pearl Harbour and the Americans entered the war directly. The huge resources of the USA were then applied without reservation to developing atomic bombs. The Manhattan Project The Americans increased their effort rapidly and soon outstripped the British. Research continued in each country with some exchange of information. Several of the key British scientists visited the USA early in 1942 and were given full access to all of the information available. The Americans were pursuing three enrichment processes in parallel: Professor Lawrence was studying electromagnetic separation at Berkeley (University of California), E. V. Murphree of Standard Oil was studying the centrifuge method developed by Professor Beams, and Professor Urey was coordinating the gaseous diffusion work at Columbia University. Responsibility for building a reactor to produce fissile plutonium was given to Arthur Compton at the University of Chicago. The British were only examining gaseous diffusion.

In June 1942 the US Army took over process development, engineering design, procurement of materials and site selection for pilot plants for four methods of making fissionable material (because none of the four had been shown to be clearly superior at that point) as well as the production of heavy water. With this change, information flow to Britain dried up. This was a major setback to the British and the Canadians who had been collaborating on heavy water production and on several aspects of the research program. Thereafter, Churchill sought information on the cost of building a diffusion plant, a heavy water plant and an atomic reactor in Britain. After many months of negotiations an agreement was finally signed by Mr Churchill and President Roosevelt in Quebec in August 1943, according to which the British handed over all of their reports to the Americans and in return received copies of General Groves' progress reports to the President. The latter showed that the entire US program would cost over $1,000 million, all for the bomb, as no work was being done on other applications of nuclear energy. Construction of production plants for electromagnetic separation (in calutrons) and gaseous diffusion was well under way.

An experimental graphite pile constructed by Fermi had operated at the University of Chicago in December 1942 ?the first controlled nuclear chain reaction. A full-scale production reactor for plutonium was being constructed at Argonne, with further ones at Oak Ridge and then Hanford, plus a reprocessing plant to extract the plutonium. Four plants for heavy water production were being built, one in Canada and three in the USA. A team under Robert Oppenheimer at Los Alamos in New Mexico was working on the design and construction of both U-235 and Pu-239 bombs. The outcome of the huge effort, with assistance from the British teams, was that sufficient Pu-239 and highly enriched U-235 (from calutrons and diffusion at Oak Ridge) was produced by mid-1945. The uranium mostly originated from the Belgian Congo. The first atomic device tested successfully at Alamagordo in New Mexico on 16 July 1945. It used plutonium made in a nuclear pile. The teams did not consider that it was necessary to test a simpler U-235 device.

The first atomic bomb, which contained U-235, was dropped on Hiroshima on 6 August 1945. The second bomb, containing Pu-239, was dropped on Nagasaki on 9 August. That same day, the USSR declared war on Japan. On 10 August 1945 the Japanese Government surrendered. The Soviet bomb Initially Stalin was not enthusiastic about diverting resources to develop an atomic bomb, until intelligence reports suggested that such research was under way in Germany, Britain and the USA. Consultations with Academicians Ioffe, Kapitsa, Khlopin and Vernadsky convinced him that a bomb could be developed relatively quickly and he initiated a modest research program in 1942. Igor Kurchatov, then relatively young and unknown, was chosen to head it and in 1943 he became Director of Laboratory No.2 recently established on the outskirts of Moscow. This was later renamed LIPAN, then became the Kurchatov Institute of Atomic Energy. Overall responsibility for the bomb program rested with Security Chief Lavrenti Beria and its administration was undertaken by the First Main Directorate (later called the Ministry of Medium Machine Building).

Research had three main aims: to achieve a controlled chain reaction; to investigate methods of isotope separation; and to look at designs for both enriched uranium and plutonium bombs. Attempts were made to initiate a chain reaction using two different types of atomic pile: one with graphite as a moderator and the other with heavy water. Three possible methods of isotope separation were studied: counter-current thermal diffusion, gaseous diffusion and electromagnetic separation. After the defeat of Nazi Germany in May 1945, German scientists were "recruited" to the bomb program to work in particular on isotope separation to produce enriched uranium. This included research into gas centrifuge technology in addition to the three other enrichment technologies. The test of the first US atomic bomb in July 1945 had little impact on the Soviet effort, but by this time, Kurchatov was making good progress towards both a uranium and a plutonium bomb. He had begun to design an industrial scale reactor for the production of plutonium, while those scientists working on uranium isotope separation were making advances with the gaseous diffusion method.

It was the bombing of Hiroshima and Nagasaki the following month which gave the program a high profile and construction began in November 1945 of a new city in the Urals which would house the first plutonium production reactors -- Chelyabinsk-40 (Later known as Chelyabinsk-65 or the Mayak production association). This was the first of ten secret nuclear cities to be built in the Soviet Union. The first of five reactors at Chelyabinsk-65 came on line in 1948. This town also housed a processing plant for extracting plutonium from irradiated uranium. As for uranium enrichment technology, it was decided in late 1945 to begin construction of the first gaseous diffusion plant at Verkh-Neyvinsk (later the closed city of Sverdlovsk-44), some 50 kilometres from Yekaterinburg (formerly Sverdlovsk) in the Urals. Special design bureaux were set up at the Leningrad Kirov Metallurgical and Machine-Building Plant and at the Gorky (Nizhny Novgorod) Machine Building Plant.

Support was provided by a group of German scientists working at the Sukhumi Physical Technical Institute. In April 1946 design work on the bomb was shifted to Design Bureau-11 -- a new centre at Sarova some 400 kilometres from Moscow (subsequently the closed city of Arzamas-16). More specialists were brought in to the program including metallurgist Yefim Slavsky who was given the immediate task of producing the very pure graphite Kurchatov needed for his plutonium production pile constructed at Laboratory No. 2 known as F-1. The pile was operated for the first time in December 1946. Support was also given by Laboratory No.3 in Moscow -- now the Institute of Theoretical and Experimental Physics -- which had been working on nuclear reactors. Work at Arzamas-16 was influenced by foreign intelligence gathering and the first device was based closely on the Nagasaki bomb (a plutonium device). In August 1947 a test site was established near Semipalatinsk in Kazakhstan and was ready for the detonation two years later of the first bomb, RSD-1.

Even before this was tested in August 1949, another group of scientists led by Igor Tamm and including Andrei Sakharov had begun work on a hydrogen bomb. Revival of the 'nuclear boiler' By the end of World War II, the project predicted and described in detail only five and a half years before in the Frisch-Peierls Memorandum had been brought to partial fruition, and attention could turn to the peaceful and directly beneficial application of nuclear energy. Post-war, weapons development continued on both sides of the "iron curtain", but a new focus was on harnessing the great atomic power, now dramatically (if tragically) demonstrated, for making steam and electricity. In the course of developing nuclear weapons the Soviet Union and the West had acquired a range of new technologies and scientists realised that the tremendous heat produced in the process could be tapped either for direct use or for generating electricity. It was also clear that this new form of energy would allow development of compact long-lasting power sources which could have various applications, not least for shipping, and especially in submarines.

The first nuclear reactor to produce electricity (albeit a trivial amount) was the small Experimental Breeder reactor (EBR-1) designed and operated by Argonne National Laboratory and sited in Idaho, USA. The reactor started up in December 1951. In 1953 President Eisenhower proposed his "Atoms for Peace" program, which reoriented significant research effort towards electricity generation and set the course for civil nuclear energy development in the USA. In the Soviet Union, work was under way at various centres to refine existing reactor designs and develop new ones. The Institute of Physics and Power Engineering (FEI) was set up in May 1946 at the then-closed city of Obninsk, 100 km southwest of Moscow, to develop nuclear power technology. The existing graphite-moderated channel-type plutonium production reactor was modified for heat and electricity generation and in June 1954 the world's first nuclear powered electricity generator began operation at the FEI in Obninsk. The AM-1 (Atom Mirny -- peaceful atom) reactor was water-cooled and graphite-moderated, with a design capacity of 30 MWt or 5 MWe.

It was similar in principle to the plutonium production reactors in the closed military cities and served as a prototype for other graphite channel reactor designs including the Chernobyl-type RBMK (reaktor bolshoi moshchnosty kanalny -- high power channel reactor) reactors. AM-1 produced electricity until 1959 and was used until 2000 as a research facility and for the production of isotopes. Also in the 1950s FEI at Obninsk was developing fast breeder reactors (FBRs) and lead-bismuth reactors for the navy. In April 1955 the BR-1 (bystry reaktor -- fast reactor) fast neutron reactor began operating. It produced no power but led directly to the BR-5 which started up in 1959 with a capacity of 5MWt which was used to do the basic research necessary for designing sodium-cooled FBRs. It was upgraded and modernised in 1973 and then underwent major reconstruction in 1983 to become the BR-10 with a capacity of 8 MWt which is now used to investigate fuel endurance, to study materials and to produce isotopes.

The main US effort was under Admiral Hyman Rickover, which developed the Pressurised Water Reactor (PWR) for naval (particularly submarine) use. The PWR used enriched uranium oxide fuel and was moderated and cooled by ordinary (light) water. The Mark 1 prototype naval reactor started up in March 1953 in Idaho, and the first nuclear-powered submarine, USS Nautilus, was launched in 1954. In 1959 both USA and USSR launched their first nuclear-powered surface vessels. The Mark 1 reactor led to the US Atomic Energy Commission building the 60 MWe Shippingport demonstration PWR reactor in Pennsylvania, which started up in 1957 and operated until 1982. Since the USA had a virtual monopoly on uranium enrichment in the West, British development took a different tack and resulted in a series of reactors fuelled by natural uranium metal, moderated by graphite, and gas-cooled. The first of these 50 MWe Magnox types, Calder Hall-1, started up in 1956 and ran until 2003. However, after 1963 (and 26 units) no more were commenced.

Britain next embraced the Advanced Gas-Cooled Reactor (using enriched oxide fuel) before conceding the pragmatic virtues of the PWR design. Nuclear energy goes commercial In the USA, Westinghouse designed the first fully commercial PWR of 250 MWe, Yankee Rowe, which started up in 1960 and operated to 1992. Meanwhile the boiling water reactor (BWR) was developed by the Argonne National Laboratory, and the first one, Dresden-1 of 250 MWe, designed by General Electric, was started up earlier in 1960. A prototype BWR, Vallecitos, ran from 1957 to 1963. By the end of the 1960s, orders were being placed for PWR and BWR reactor units of more than 1000 MWe. Canadian reactor development headed down a quite different track, using natural uranium fuel and heavy water as a moderator and coolant. The first unit started up in 1962. This CANDU design continues to be refined. France started out with a gas-graphite design similar to Magnox and the first reactor started up in 1956.

Commercial models operated from 1959. It then settled on three successive generations of standardised PWRs, which was a very cost-effective strategy. In 1964 the first two Soviet nuclear power plants were commissioned. A 100 MW boiling water graphite channel reactor began operating in Beloyarsk (Urals). In Novovoronezh (Volga region) a new design -- a small (210 MW) pressurised water reactor (PWR) known as a VVER (veda-vodyanoi energetichesky reaktor -- water cooled power reactor) was built. The first large RBMK (1,000 MW - high-power channel reactor) started up at Sosnovy Bor near Leningrad in 1973 and in the Arctic northwest a VVER with a rated capacity of 440 MW began operating. This was superseded by a 1000 MWe version which became a standard design. In Kazakhstan the world's first commercial prototype fast neutron reactor (the BN-350) started up in 1972, producing 120 MW of electricity and heat to desalinate Caspian seawater.

In the USA, UK, France and Russia a number of experimental fast neutron reactors produced electricity from 1959, the last of these closing in 2009. This left Russia's BN-600 as the only commercial fast reactor. Around the world, with few exceptions, other countries have chosen light-water designs for their nuclear power programs, so that today 60% of the world capacity is PWR and 21% BWR. The nuclear power brown-out From the late 1970s to about 2002 the nuclear power industry suffered some decline and stagnation. Few new reactors were ordered, the number coming on line from mid 1980s little more than matched retirements, though capacity increased by nearly one third and output increased 60% due to capacity plus improved load factors. The share of nuclear in world electricity from mid 1980s was fairly constant at 16-17%. Many reactor orders from the 1970s were cancelled. The uranium price dropped accordingly, and also because of an increase in secondary supplies. Oil companies which had entered the uranium field bailed out, and there was a consolidation of uranium producers.

However, by the late 1990s the first of the third-generation reactors was commissioned - Kashiwazaki-Kariwa 6 - a 1350 MWe Advanced BWR, in Japan. This was a sign of the recovery to come. Nuclear revival In the new century several factors have combined to revive the prospects for nuclear power. First is realisation of the scale of projected increased electricity demand worldwide, but particularly in rapidly-developing countries. Secondly is awareness of the importance of energy security, and thirdly is the need to limit carbon emissions due to concern about global warming. These factors coincide with the availability of a new generation of nuclear power reactors, and in 2004 the first of the late third-generation units was ordered for Finland - a 1600 MWe European PWR (EPR). A similar unit is being built France as the first of a possible full fleet replacement there, and more are planned in the UK. In the USA the 2005 Energy Policy Act provided incentives for establishing new-generation power reactors there, and the first four AP1000 reactors are under construction.

But plans in Europe and North America are overshadowed by those in China, India and South Korea. China alone plans and is building towards a huge increase in nuclear power capacity by 2020, and has more than one hundred further large units proposed and backed by credible political determination and popular support. A large portion of these are the latest western design, expedited by modular construction. The history of nuclear power thus starts with science in Europe, blossoms in UK and USA with the latter's technological might, languishes for a few decades, then has a new growth spurt in east Asia. Main sources: Atomic Rise and Fall, the Australian Atomic Energy Commission 1953-1987, by Clarence Hardy, Glen Haven, 1999. Chapter 1 provides the major source for 1939-45. Radiation in Perspective, OECD NEA, 1997. Nuclear Fear, by Spencer Weart, Harvard UP, 1988. Judith Perera (Russian material).

Question: Where was the first nuclear reactor built, by Enrico Fermi?
Answer: Chicago